Medicine by machine: Is A.I. the cure for the world’s ailing drug industry?

When a Canadian company called Deep Genomics announced in September that it had used artificial intelligence to solve a long-standing mystery about a genetic disorder called Wilson’s disease—and, what’s more, had used another deep-learning platform to identify a potential treatment—there was a flurry of excitement in the drug development world. The apparent milestone, which the company hailed as the “first-ever A.I.-­discovered therapeutic candidate,” got echoing headlines from dozens of news outlets, and in January, the five-year-old startup received a $40 million endorsement in the form of a fresh round of...